Means for decreasing leakage in turbines.



No. 841,650. I PATENTED JAN. 15, 1907.

' 0. JUNGGREN.

MEANS FOR DEOREASING LEAKAGE IN TURBINES. APPLICATION FILED JU'KE'30,1906.

r Inventor-:-

Oscar-duh gran,

v B%% oqttfy Vvitnesses:

and through this clearance considerable plish this I provide a meanswhereby a hi 'h Schenectadv, in the county of Schenectady,

'Decreasing the Leakage in. Elastic-Fluid.

. stationary or intermediate buckets which reagainst a second set ofwheel-buckets Manileakage or escape of motive fluid.

cover, the surface friction opposing the eswarren same rarn v r option.

OSCAR JUNGGREN, or scHENncrAnr ELECTRIC COMPANY, A CORPORATION OF. NEWYORK.

MEANS FOR DECREASING LEAKAGE lN TURBINES.

' Specification of Batters-Patent.

Patented Jan. 15,1907.

Original application filed April 29,1903, Serial N01 154,888 Divided andthis application filed J'nne'BO, 1906. Serial No. 324,238.

To all whom; it may concern:

Be it known that I, OSCAR JUNGGREN, a citizen of the United States,residing at State of New York, have invented certain new and usefulImprovements in Meansfor Turbines, of which the following is aspecification.

This application is a division of my pending application, filed April29, 1903, Serial ,No. 154,888. V

In elastic-fluid turbines it is customary to provide a cover forthe'outer ends of the wheel-buckets in order to confine the motive fluidto the passages between the buckets. Situated between the wheelbucketsare celve the motive fluid from one set oi. wheel-' buckets anddischarge it at the proper angle festly there must be a clearance moreor less great between the relatively moving buckets,

steam or, other motive fluid leaks. The amount of this leakage is alsogoverned by the difference in pressure betweenthe column of steamactually performing work and that in the surrounding casing or shell.The greater the diflerence in pressure, other things being equal, thegreater the leakage.

My invention has'for its object to decrease the leakage at theclearances, and to accomresistance or opposition is offered to t e Thecovers ordinarily employed on the wheel-buckets are very thin, varyingin thickness from one-eighth to threesixteenths of an inch. Owing to thethinness of the cape of steam is very small.

In carrying out my invention I provide the bucket-covers with thickenededges, taking the form of circumferential flanges formed integraltherewith. The extended surfaces of the thickened edge of the cover andthe support for the intermediates oiier a considerably higher-resistanceto the escape of motive fluid than does the normal passage between thebuckets. The opposition or resistance to leakage is not so great,howaver,

expansion from-being discharged under centrifugal force. The amount thatthe flange or flanges project beyond the cover varies with the characterand size of the turbine.

For a fuller consideration of what I believe to be novel and of myinvention attention is called to the description and claims appendedthereto.

In the accompanying drawings, which illustrate one embodiment of myinvention, Figure 1. is a partial axial section of a turbine. Fig. 2 isa sectional view of a wheel, taken on the line 2 2 of Fig. 1.

, NEWYORK, ASSIGNOR TO GENERAL 1 represents the turbine casing or shell,and

secured thereto is an adjustable nozzle 2, which may be of the expandingor non-exv .panding type, as is desired. In the particular illustrationit is .intendedto convert the pressure of the elastic fluid intovelocity and deliver it in the form of a jet to the buckets;

but my invention is not limited thereto.

The no'zzle'is secured in place by bolts 3 and is adjustable toward andaway from the' wheel in a plane parallel to its axis. The

side of the casing or shell is provided with an opening through whichprojects the See;

mental support for the intermediate buckets.

The support is provided with a flange 4 of,

somewhat greater areathan the opening, I, which is secured to theoutside of the cas-' ing by bolts 5. Between the bodies of the bolts andthe flange is a space, so. t-hatthe intermediates oan'beadjnsted in anaxial plane for the purpose. of changing the clearances between them andthe wheel-buckets.

The intermediate buckets 6 may be of any suitable shape and form and aresecured to their support-in any ordinary manner. The

intermediate buckets are provided with covers 7, which are slightlywider than the buckets themselves measured. in an axial plane. The

portion 8 of the vsupport adjacent to the wheel-bucket cover isalso"somewhat wider than the buckets measured in an axial plane, so asto reduce the leakage and preventv the sharpened edges of the bucketsfrom rubbing.

The wheel-buckets 9 are each provided with a shank 10, formed integraltherewith at the inner end, and these shanks are fitted into acircumferential groove formed in projections onv the periphery of thewheel 11. The

[buckets are retained in place by pins 12,

which extend from one side to the other. '61- cross leakage at thispoint.v

fling strip, which cover edges formed .mediate support, is made asconsistent .with good operation.

this clearance the water due the said projection or'raised portionformed on the wheel periphery. The pins, being somewhat shorter than thedistance between 1 the projections, can readily be slippedinto place andthe ends peened over afterward. I The sides of the-projection areiinclose proX; imity to the cover 7 of .the intermediate buckets, so as toreduce the circumferential or The buckets may be formed by drb'p-forgingor casting, as desired, and each-bucket is provided with a cover 13.,sometimes called a "fitting and bafhas two thickened integral therewith,whichin the present illustration take the form of circumferentialflanges L1,. In cross-section. the cover has the shape of achannel-beam. The clearance, measured in 'an axial plane, between thethickened edges or flanges 14 of the bucket-cover and-the stationaryparts, such as the nozzle andtthe portion 8 of the intersmall as ossiblehrough to expansion and discharged; but the repassage ofelascondensation can be- 'tic motive fluid at this point is high. Thisis siderably owing to the fact that the flange presents an extendedsurface to the stationary part, and the frictional resistance offered tothe outward passage ofsteam at this point is congreater than theresistance offered a to the passage of steam through the normal or steamor other elastic working passages between the buckets. In

other words, two paths are provided for the fluid-one of lowresistance'and the other of relatively high'resistanceand owing to thefact that the jet istraveling at high velocity dueto the nozzle onlyavery small amountof stearnwill be permitted to escape through thecircumferential clearance. The water 'due toexpansion and condensationalso has a tendency to decrease 'tlieleakage by wetting theadjacentsurfaces of the moving and stationary parts. I As theintermediate buckets usually extend around only a smallportion of thewheel, the brake action due to the Water can be disregarded. Underordinary conditions of operation, however,

prevent this brakeactmnfrorn taking place, i

at least to any substantial'degree. The flange, 14 has considerabledepth meas ured in-a radial plane, and this depth varies with differentturbines. As a general propothat the greater the diflerence 1n pressurebetween the fluid stream and fluid within the shell or casing thegreater will be the depth of the flange, because the tendency of thesteam-to escape at this pointis correspondingly increased.

Referring to Fig. 2,.it willbe seen that the of accidental rubbing ofthe parts tion with a casing, attached thereto,

the clearance would be great enough to l shank 11) on each bucketistapered and enageswith similar shanks on adjacent bucki ots and thatthe cover 13- of each bucket is l also slightly tapered and engages withthe. r

' In this cover-sectmns of adjacent buckets. manner the steam or othermotive fluid is con fined to the working passages 15.

The baffling of the motive fluid may take place at the side llanges oi?the fitting and bafflingstrip or cover 12$, as shown in connection withthe intermediate bucket-supports b, or the edges of the flanges on saidstrip may be utilized for the purpose, the structure-being the same ineither case. The said strip can serve as a bafliing means on both theside and edge at the same time, as shown in the upper right-hand cornerof lig. 1.

The bafller df closed herein possesses important advantages over priorarrangements in the way of ociter bafliing effects and in the way ofgreatly-decreasedcost of manufacture. It is also well adapted to meetthe condition By makout of solid stock with flanges ing the stripsthereto it is a simple and inexat right angres pensive matter to turn orflIllSll' the face or.

faces to the required dimensions. Moreover, such a construction rendersit possible to utilize workmen of ordinary skill.

In accordance with the provisions of. the patentstatutes I havedescribed the principle of operation of my invention, together with theapparatus which I now consider to represent the best embodiment thereof,but- I desire to have it understood that the apparatus shown is onlyillustrative and that, the invention can be, carried out in other ways.

I/Vhat'I claim as new, and desire to secure by Letters Patent of theUnited States, is- 1. Inanelastic-fluid turbine, the combinaof a wheelhaving buckets each bucket having an integrally-formed cover withoutwardly-projecting flanges.

2. In an e1 astic-fluid turbine, the combination with a casing, of awheel having buckets attached thereto, each bucket having anintegrally-formed cover with outwardly-projecting flanges, and astationary element having a surface in close proximity to one of saidflanges.

3. In an elastic-fluid turbine, the combination-with a casing, of a.wheel having buckets attached thereto, each bucket having anintegrally-formed cpver with outwardly-projecting'flanges, and anintermediate bucketsupport situated in line with and in close proximityto one of said flanges.

4. In anelastic-fluid turbine, the combination with a casing, of a wheelhaving buckets attached thereto, each bucket having an in;tegrally-formed cover with outwardly-pro jecting flanges and astationary element having surfaces in close proximity to the side andedge or one of said flanges.

5. In an elastic-fluid turbine, the combina tion with a casing, of a whaving tegrally-formed cover with outwardly-pro- I ecti fla es, the liii ckel s to latter from rub 6. In an elastic fluid turbine, thecombination with a casin of a Wheel having buckets attached thereto,each bucket having an integrally-formed cover in the shape of achannel-beam.

- 7. In an elastic-fluid turbine, the combination with a casing, of awheel having buckets attached thereto, each bucket having anintegrally-formed cover in the shape of a channe'l beam and stationaryintermediate bucketsupports having flat surfaces situated in closeproximity to the sides of said channel-beam cover.

- 8. In-an elastic-fluid turbine, the combination with a wheel having onits periphery a plurality of circumferentially-grooved projections, of aplurality of buckets, each havwhich are slightly wider than rotect thesharp edges of the m mg a shank that enters the groove a retaining-pinfor each bucket passing through the shank and a projection, and an.integral cover for each bucket formed in the shape of a channel-beam.

9. In an elastic-fluid turbine, the combination with a wheel having onits periphery a plurality of circumferent-ially-grooved projections, ofa plurality of buckets, each having a shank that enters the groove, aretaining-pin for each bucket passing through the shank and aprojection, and an integral cover for each bucket formed in the shape ofa channel-beam, said covers fitting closely together to form a smoothcontinuous surface around the entire wheel.

In witness whereof I have hereunto set my hand this 29th day of June,1906.

OSCAR JUNGGREN.

Witnesses:

BENJAMIN B. HULL, HELEN ORFORD.

